[Asterisk-Users] Becoming a VOIP provider

[Nihal]

This is a bit off topic, but I'm not sure where else to start.

I've got a friend in Australia who works for a big ISP there. I guess they want to provide VOIP service to their customers.

Can anyone give us an idea how someone can, I guess, purchase phone lines to sell as VOIP lines? I'm a bit lost here, but basically what is 
needed to become a VOIP provider?

Would you buy a bunch of phone lines and hook them up to something like Asterisk, then provide SIP connections?

We dont need to know Australia specific, just trying to get an idea where to get started.

Thanks for your help!

Nihal Titan